1. Field of the Invention
The present invention relates to a method of tapering a toothbrush bristle, which increases production efficiency, and, more particularly, to a method of tapering a toothbrush bristle, which increases production by three or more times.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98
A method of tapering a polyester toothbrush bristle uses a principle in which, when a polyester fiber is immersed into a heated sodium hydroxide solution, part of the fiber is dissolved. Japanese Examined Utility Model Sho 50-40195 discloses a method of tapering a tip of bristle, in which a bundle of polyester bristles is cut to a predetermined length, is vertically immersed in a sodium hydroxide solution, having a concentration of 20% and a temperature of 100° or more, to a depth of about 5 mm, and is then dissolved (hydrolyzed), based on this principle.
Furthermore, Korean Patent No. 10-0130932 discloses a method of tapering a monofilament for a toothbrush, in which a bundle of toothbrush bristles is dissolved in sulfuric acid, having a concentration of 80˜90% and a temperature of 80˜200°, and is thus tapered.
Japanese Unexamined Utility Model Sho 57-12934 discloses a technology of manufacturing brushes by implanting bristles, each of which has a taper at one end thereof without folding, or bristles, each of which has tapers at both ends thereof and folded in half, using the above methods. Japanese Examined Utility Model Sho 61-10495 discloses a method of manufacturing a toothbrush by folding a bristle, such that a tapered part of the bristle is relatively long whereas an untapered part of the bristle is relatively short.
Moreover, Japanese Unexamined Utility Model Hei 05-15834 discloses a method of manufacturing a toothbrush by folding toothbrush bristles, each of which has tapers at both ends thereof, in half and implanting them in the head of a toothbrush. This method has been widely used.
Thus, the technology of manufacturing a toothbrush by folding toothbrush bristles has been disclosed, each folded bristle having tapers at both ends thereof, in half and implanting them in the head of a toothbrush. The toothbrush bristles are cut to a predetermined size, one end of the toothbrush bristle is dissolved by vertically immersing the tip of the toothbrush bristle into a chemical, and the other end of the toothbrush bristle is dissolved using the same method. The bristle is then cooled, neutralized, cleaned in water and dried, thereby manufacturing the double end tapered toothbrush bristle.
However, the above method has a problem in that it takes a lot of time to perform a tapering process, and the tapering process is complex. For example, when the tapering process is performed using a sodium hydroxide solution having a concentration of 40% at a temperature of 110°, it takes 80 minutes to perform the process of tapering one end of a toothbrush bristle, and another end of a toothbrush bristle must be tapered after the one end thereof is tapered.